6543636944 has 80 divisors (see below), whose sum is σ = 14006853504. Its totient is φ = 2942784000.

The previous prime is 6543636881. The next prime is 6543636947. The reversal of 6543636944 is 4496363456.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 6543636892 and 6543636901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6543636947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1662659 + ... + 1666589.

Almost surely, 2^6543636944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6543636944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7003426752).

6543636944 is an abundant number, since it is smaller than the sum of its proper divisors (7463216560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6543636944 is a wasteful number, since it uses less digits than its factorization.

6543636944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4156 (or 4150 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 50.

The square root of 6543636944 is about 80892.7496380238. The cubic root of 6543636944 is about 1870.4225592404.

The spelling of 6543636944 in words is "six billion, five hundred forty-three million, six hundred thirty-six thousand, nine hundred forty-four".